yeah good point. the thing about the cel is is isnt on all the time and usually goes away once ignition is turned off then on. Would this still show up if i were to read the codes?

 

Yes, just because the light isn't on doesn't mean there aren't codes...your computer stores them until they are fixed and cleared. How long has it been since you did a tune up? I don't know why Autozone asked you that but that question is moot. Should be the same PN even if it DID have two cats which yours won't.

 

I could be wrong as my truck has but one lowly o2 sensor, but think L & R bank ahead of the Cat are the same, but an o2 after the cat is a different P/N. On yours, if you had 2, they would both be ahead of the Cat. You run into probs at parts stores because there are a lot on transitional years, where items are for some, but not all trucks/ engines/ for that year & even state intended for license. The method "JCMS" refers to for getting Error codes is doable. That's how I first did it, but for $20:http://www.handsontools.com/Equus-In...ol_p_5574.html You can do it the hard way, or the easy way, but do it! Personally, I don't get too attached to my o2 sensor (especially as I only have 1 to replace. I tend to replace it ahead of schedule (whatever that is, everyone seems to have there own schedule). As long as I'm under the truck, changing the Synth. oil at 8K miles, I remove them & douche them w/ MAF cleaner and actually replace them anytime after 25K. One of the reasons I believe my 87' 302 gets 18/23 MPG. But when my truck's not loafing around town, I'll do 900 mile road trips (any excuse to get the h*ll out of California, especially Oregon & Washington) where I don't stop more than once per 700 miles.